Ever since 2002, Hollywood has had a case of mistaken “Bourne Identity,” pulling the trigger on any script that weaves government Intelligence with guns and combat and centers on a protagonist who doesn’t know his or her own strength. “Salt” is another byproduct of the “Bourne” era, yet barely executes half as well as that consummate secret agent thriller.

Angeline Jolie plays the titular “hero” in question, a CIA agent. When she interrogates a Russian who claims a Soviet sleeper agent will attempt to assassinate the president of Russia, she finds the finger pointed at her as that exact agent and so she goes on the run, very quickly putting her innocence out of the question, whereas the film would lead you to believe it’s a “is she or isn’t she?” movie. Whenever that’s the case, you can bet the answer lies in the gray area, but nevertheless, that’s “Salt.”

Why movie scripts can’t simply let go of old Cold War themes and plots warrants a rigorous head scratch. Writer Kurt Wimmer (“Law Abiding Citizen,” “Equilibrium”) has a history of penning films that are never as believable as they are entertaining and “Salt” follows suit. The idea of bitter “comrades” awakening sleeper agents 20 years later that they trained and planted in the USA in hopes of reigniting nuclear war might top his list of improbable.

Yet “Salt” has a nuclear warhead in Angelina Jolie, Hollywood’s most treasured femme fatale. When Tom Cruise left the project, she became the sexy choice and consequently might have saved a Cruise-led “Salt” from complete annihilation critically and financially.

Philip Noyce (“Patriot Games,” “Clear and Present Danger”) could direct a film like this in his sleep and he may well have. I was able to watch the director’s cut, which is insignificant when you don’t see the theatrical cut, but I didn’t find anything other than the action all that redeeming, so I imagine it made no difference. His expertise lies in flipping the adrenaline switch on and satisfying that part of every viewer that’s just waiting for the action to kick into gear. It’s very obvious when something will happen, but the results are less predictable than you’d expect.

The real problem with “Salt,” preposterousness aside, comes in story structure. In order for the effective twists and turns at the end (not unforeseeable, but still exciting), Wimmer and Noyce both have to downplay Salt’s character. Frankly, she sucks for most of the film. She’s a terrible protagonist because — without giving anything away — the script’s not-so-well guarded secrets are held in priority above her character development. Irrelevant flashbacks to her “husband” are an attempt at humanizing her, but her present actions become too strong for those sympathy cards to work.

Espionage thriller and action movie fans will find comfort in “Salt” and continue to be drawn to Jolie’s performances in these roles, but those who can’t keep their fingers out of plot holes and have to ponder the feasibility of a story will be frustrated throughout most. For me, the twists at the end sorting the film out and making it “matter” more saved it from total mediocrity.